Mods I hope its OK to post here AND in the Technical Forum.....if not apologies and please delete. My 2002 998r is only running on the vertical cylinder, Ive established that the HT leads and coils are OK and so are the plugs. I’ve run the diagnostics using VDSTS and there are no error messages and all the tests ran fine. The belts are OK too. There is no spark when I earth the plug and turn the engine over and there does no appear to be fuel in the cylinder either as the plug remains dry even after I run the engine on one cylinder…..Im baffled! Any thoughts?
So presumably you have swapped over the coils and leads etc to confirm they work...........what about the cpu do you know of another 998 near you you could try to confirm it sparks if nothing else?
Thanks for the reply. Yes Im worried about the ECU (€1400 for a replacement!!) I assumed that if the ECU was a problem it either wouldnt run the diagnostics or I would get a Trouble code showing. There are no trouble codes and it ran the diagnostics fine....beats me!
where are you? Why not get it on a dyno to fault find.......i bet somewhere like CJS could supply fit and dyno set up an ecu for half that sort of money.....
Thanks for the reply. Yes I've swapped the coils, plugs and HT leads and caps and all work fine on the vertical cylinder but nothing works on the horizontal. 998rs are as rare as hens teeth here in Ireland so the chance of swapping out the ECU is remote. There is a company that 'repairs' ECUs but I'm as wary of them as I am of our local dealer.
the cpu is more common than calling it a 998R unique bit of kit have you searched ebay and all the regular haunts? failing that search CJS a chap called chris, i bet he can help even if its posting out another cpu for you to try......dont ask dont get!
I had similar symptoms on my ST4S which has 996 motor, and I'm affraid it was the ECU. Hope I'm wrong but I bet that is your problem. Good luck. Try an ECU of anything, it might not run right but if it runs on two cylinders you have pin pointed the problem. My mechanic used a 999 ECU to test the ST. Just need the right style of ECU.
It's always difficult faulting over the internet but "I’ve run the diagnostics using VDSTS and there are no error messages and all the tests ran fine" does give a pointer in that the ECU may not be able to see the problem. i.e. its mechanical, have you got comression on the horizontal cylinder, is the injector actually firing and allowing fuel in etc? As its a 998R I'll buy it off you for scrap
The ecu can drop a coil driver. Avanti can diagnose and repair if needed. Drop antonye a pm on here. Only strange thing is the plug being dry as well. This could be a problem with the crank sensor as the info from this fires the spark and the injector. Check to see if you have 12v at the coil and the injectors. They are fed from a common 12 v feed and the ecu switches the earth to trigger them.
Thanks for all the replies guys.....am I the only one who misses carbs, with all that good s**t like jets and needles and float valves. I'll take on board all the suggestions and post any progress. Even if it doesnt run I can still look at it. Kevski, thanks for the kind offer.....but dont hold your breath.Please please don't mention checking compression in any future posts.....it doesnt bear thinking about.
A crank position sensor would be the cheaper fix. I've not done any work with 998's but I could create an ECU for you to try. Are you able to post the details on the labels on the ECU? I can then loan you an ECU to try. All you have to pay is the postage costs.
Guys, I'm overwhelmed by the replies and offers of help, thanks to everyone. I'm going to collect my thoughts and try a few more things including the crank position sensor (again) I'll keep you posted. Chrisw, thanks for your really generous offer......you may be hearing from me. The Guinness is on me when any of you are in Dublin!!
My 2002 998s had an ecu marked as 996R/998s/998r i'm sure. That broadens the scope for a replacement. Perhaps someone that still has one of these can confirm what theirs says. If so you could get one cheap enough to try.
ECUs can be marked as anything - they often get recycled at the factory, stickers drop off, etc. It's what's on it that counts! It's most likely the coil driver and you can test that as Nelly says above. They are repairable, and they are also replaceable. If you need either, just drop me a pm.
He means the ECU. The 998R was originally supplied with two ECU's. Chances are he doesn't have it if he bought the bike second hand.
